This self-loading striker-trigger mechanism is meant to be built in automatic and semi-automatic firearms of the kinds: pistols, machine guns and submachine guns for automatic and semi-automatic fire.
Known striker-trigger mechanisms for building in handguns fall into two major types:
The first type are striker-trigger mechanisms with a striker. This type of striker-trigger mechanisms involve a hammer mechanism coupled with a trigger mechanism. The hammer mechanism includes a striker interacting with a firing pin spring. Under the impact of the firing pin spring the striker rotates to hit a firing pin (a prolate pin-shaped body), which flies ahead and hits the (primer) capsule of a cartridge in the chamber and executes a shot.
This type of striker-trigger mechanisms come with two kinds of trigger mechanismsxe2x80x94for singlexe2x80x94 and double-action modes of operation respectively.
With the single-action trigger mechanisms after loading the weapon, that is feeding a cartridge in the chamber of the barrel, the striker can be manually lowered without producing a shot and then manually set into combat position right before the firing.
The double-action trigger mechanisms of the above referred type are applicable in submachine and machine guns. With them the combat position of the striker is achieved through pressing the trigger.
With the submachine guns this known striker-trigger mechanism employs a device for shot separation and safety tools.
With the machine firearms there is also a fire selecting mechanism for automatic and semi-automatic fire.
The weaknesses of this traditional type of striker-trigger mechanisms are:
With the single-action striker-trigger mechanisms to carry the gun in a ready-to-fire state after loading it, the striker has to be manually dropped without firing; and later right before shooting to be manually set into firing position, all of which takes time.
With the double-action striker-trigger mechanisms the striking hammer is put into firing position by means of pulling the trigger. The first shot, then, requires prolonged and heavy motion of trigger, unlike second and subsequent shots fired by brisk and smooth trigger motion. That forces the user into getting accustomed to two kinds of trigger motionsxe2x80x94the long and heavy one causes deviation and accuracy reduction.
The second type is a single-action striker-trigger mechanism employing a firing pin in direct link with a firing pin spring, which is either coiled around it or placed behind it. In this kind of striker-trigger mechanisms the firing pin gets into combat position, firing pin spring cocked, simultaneously with loading the gun, i.e. with issuing a cartridge into the chamber.
A shortcoming of this known type of mechanism is that carrying the gun ready-to-fire, the spring is exerted all the time, which leads to its fatigue over time, while a major requirement for modern firearms in military or law-enforcement use, is to allow to be carried for a long time without depreciation being caused to their mechanics.
The invention aims at devising a self-loading striker-trigger mechanism for semi-automatic and automatic fire featuring simple construction and enhanced security upon carrying the firearms loaded no safety, capable of eliminating any possibility of accidental discharge, and with the trigger motion smooth and equally long for each shot in automatic or semi-automatic fire modes.
The solution to the task is a self-loading striker-trigger mechanism for machine guns and submachine guns, which consists of a striker mechanism, trigger mechanism and a fire selecting mechanism for switching from automatic to semi-automatic fire. The striker mechanism includes a firing pin fixed in a breach block mounted in the upper rear end of the frame of the firearm. The firing pin has a pointed front end with a firing pin spring coiled around it. The trigger mechanism mounted below has a trigger to set firing pin into combat position. As per this invention the striker mechanism, the trigger mechanism and the fire selecting mechanism have been put together in a single unit in the form of a rear block. The fire selecting mechanism is accomplished as a fire select placed in the rear part of the frame. Inside the rear central part of the breach block longitudinally a step-like channel has been run to house the firing pin fitted with a profile tooth, designed to mesh with the trigger mechanism, whose trigger is equipped with a spring to push the trigger back. The trigger is joint-linked to the frame. Again joint-linked to the trigger comes a profile one-arm lever in the form of a trigger bar, pressed to the breach block by another spring. The trigger bar has a contact firing tooth with the striking mechanism, coming as an upper lug sideways to the trigger bar.
Optionally the self-loading striker-trigger mechanism for machine and submachine firearms, as per this invention, can be realized with the striker mechanism having enlargements at both endsxe2x80x94front and rear enlargements respectively. The lower end of the rear enlargement has the profile tooth engaging with the firing tooth on the trigger mechanism. Both teeth""s profiles correspond. Central to the front enlargement of the firing pin is its front pointed end. Between the two enlargements two axially moving spring cups are positioned with external diameters more and internal diameters less than the external diameter of the enlargements, so that their axial movement is restricted by them. The two axially moving cups are separated by the volute firing pin spring coiled around the firing pin, which has a diameter less than the external diameters of the cups, hence holding the cups within their allocated enlargements. The striking mechanism thus shaped as a unit is mounted, along the same axis as the gun""s barrel, in the step-like lidded channel in the rear central area of the breach block, with front and rear props to space the axial movement of the movable cups.
Another optional realization of the self-loading striker-trigger mechanism for machine and submachine firearms, as per this invention, features a lengthwise cut-out in the lower rear part of the step-like channel of the breach block, parallel to its longitudinal axis, holding the profile tooth to the rear enlargement of the firing pin so that it protrudes outside the longitudinal cut-out. The step-like channel is constricted in its front part and shapes a step-like tightening, whose foremost surface is the front prop for the spring cup in extreme foremost position. The front part of the step-like aperture has minimal diameter for the front pointed end of the firing pin to come in; while in its rear part, maximal in diameter, rests stationary the rear prop for the movable cup in the form of sleeve. In the longitudinal cut-out area the sleeve has a lengthwise fuller as wide as the longitudinal cut-out in the step-like channel and fitting so that the tooth of the firing pin be able to move freely along its longitudinal axis. Sleeve""s outside diameter equals the diameter of the rearmost, widest part of the step-like channel, while the inside diameter of the sleeve is a little larger than the rear enlargement of the firing pin, so that it can move freely along and the firing pin can move unhindered along the axis.
A possible realization under this invention of the self-loading striker-trigger mechanism for machine and submachine firearms works with the sleeve stationaryxe2x80x94fixed in the rear part of the step-like channel in the breach block by means of a fixing tooth.
A possible realization under this invention of the self-loading striker-trigger mechanism for machine and submachine firearms optionally has the firing pin tooth with a flat front surface/area square to the axis of the firing pin and rear surface/area slanting to this axis; while the firing tooth is with flat rear surface, also square to the axis of the firing pin and slanting front surface corresponding with the slanting surface of the firing pin tooth.
Another option for realization of the self-loading striker-trigger mechanism for machine and submachine firearms works with the spring of the trigger mechanism, made of spring wire, around a stationary axle mounted to the rear block. One arm of this spring presses the lower part of the trigger bar, parallel to the axis of the firing pin, to fall within a longitudinal groove made there for it; and below the second arm of the spring there is a support, part of the rear block, parallel to the axis of the firing pin, so that the spring presses the trigger bar upwards to the inside of a ramp-channel with slanting rear surface made in the lower rear part of the breach block, parallel to the axis of the firing pin.
The self-loading striker-trigger mechanism for machine and submachine firearms under the object of this invention can be realized with the trigger i suspending from an axle attached to the frame and passing through a canal made in its upper part. The front foremost surface of the above mentioned upper part upholds the helical spring for trigger return, coiled around the axle. The upper part of the trigger has a second axle set up, which fits with the trigger bar in a bearing in the upper rear part, where the arcuated lug lies and the firing tooth situated in the rearmost surface of the trigger bar. The trigger bar will have to employ a tooth to be spring-retainedxe2x80x94spring provided in the rear block.
The self-loading striker-trigger mechanism for machine and submachine firearms, as per this invention, would preferrably be accomplished so that the rear block is positioned in the upper rear part of the frame having the fire select connected by means of an arm with tilting inside surface propping the upper bent end of the spring retention, whose second end fits in a cut-out in the rear part of the rear block. The arm of the fire select fits (bearing) with a stationary axle in the rearmost part of the frame and is in contact with a fixing pin and a spring.
The advantages of the self-loading striker-trigger mechanism as proposed by this invention will be as follows:
This mechanism features a simple structure and its operation disnecessitates the safety as unintentional shots are prevented from going off, eliminated by the design of the striker and trigger mechanisms engaging through their teeth with matching profiles.
Also advantageous is the possibility to carry the gun loaded, since the firing pin spring is cocked directly and only by pulling the trigger. No less a contribution to the existing level of technology in terms of facilitated utilization, is the fact that the self-loading striker-trigger mechanism""s configuration implies rectilinear movements of the trigger, smooth and equally long for all shots. Accidental discharge is impossible with it, since the the firing tooth of the trigger bar within the trigger mechanism is positioned before the tooth of the firing pin, hence functions as safety. Thus a shot cannot be fired.